Selective telegraph system



July 5 1927 1,635,131 [-1. L. KRUM SELECTIVE TELEGRAPH SYSTEM Orizinal Filed June 30. 1 1

lhaerzior/ Jfozmrd L. [071m Patented J l 5 1 i l UNITED STATES PATENT omcs.

HOWARD L. KRUM, OF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS, TO MORKRU'M-KLEINSCHMIDT CORPORATION, OF CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE.

SELECTIVE TELEGRAPH SYSTEM.

Original application filed June 30, 1916. Serial No. 106,925. Patent No. 1,434,290, dated October 31, 1922. Divided and this application filed October 30. 1922, Serial No. 597,896. Renewed May 10, 1927.

The present application is a division of my prior application, Serial No. 106,925, filed June 30, 1916, Patent No. 1, 134,290,dated October 31, 1922.

The invention relates to selective or automatic printing telegraphs having selective transmitting and receiving switch mechanisms and means for maintaining the receiving switch mechanism at one station in synchronism with the transmitting switch mechanism at another station.

The present invention seeks to provide a selective telegraph system of this sort in which improved circuits are employed in effecting the synchronous operation of the transmitter and receiver mechanisms at the connected stations. To this end I employ a novel'normally open line circuit in as sociationwith a line relay having its tongue normally resting in a mid-position between two contacts but responsive to' current of one polarity to engage one contact and to current of the opposite polarity to engage the other contact and with said relay I control the receiver distributing mechanism and the operation of the receiver magnets.

Another object of the invention is to increase the speed of operation. This is accomplished by a novel arrangement by which the first impulse of the transmitted signal, whether positive or negative, releases the receiver mechanism. Thus I utilize part of the energy of the signal itself to start the receiver.

The various features and objects of the invention will be more fully understood upon reference to the following, detailed description taken in connection with the accompanying drawing, while the scope of the invention will be particularly pointed out in the appended claims.

The figure of the drawing is a diagram of circuits arrangedaccording to the present invention and connecting two stations, one a transmittingstation and the other a receiving stations i The receiversw-itch mechanism which I employ is fully described in the aforesaid parent case, but certain of its parts are shown in the drawing. These include a rotating switch arm a and a circular series of cooperating contacts fixed to an insulating disk A. Preferably, the disk is arranged pointed out in the aforesaid case.

so that the contacts may be adjusted, as fully The switch arm a is mounted upon a sleeve 17 which, in turn, is mounted upon a shaft 18. The fit is loose and, consequently, the sleeve 17 may be rotated freely upon the shaft 18. The latter extends through a central opening in the diskA. As pointed out more fully in the parent case, the shaft 18 is continuously driven by a motor, the speed of which is maintained constant. The sleeve 17 is driven by the shaft 18 through the medium of a yielding friction device.

For this purpose the shaft has secured to it a. disk-like portion 25, having a laterally projecting edge flange 26, and a hub 27 fixed tothe adjacent end of the sleeve 17 is provided with a series of curved s rings 28,

each of which engages the inner ace of the flange 26 through an arc of considerable size. The friction disk 25 and flange 26 are preferably formed ofcast iron and the springs of hardened steel. The inner ends of the latter are suitably secured to the hub 27 and at their outer ends are pressed snugly against the inner face of the flange 26. These parts afford a secure connection be tween the shaft and the sleeve so that the latter is properly driven. But the connection is such that the sleeve and receiver switch carried thereby can be arrested, since the connection between the sleeve and the shaft afforded by the springs 28 and the friction disk will yield or slip. The space within the flange 26 is ordinarily enclosed and filled with a suitable lubricant to prevent undue wear of the springs 28.

A disk 31 fixed to the sleeve 17 is pro vided with ashoulder 32 which normally engages a stop arm 33. The latter constitutes the armature of a trip magnet C and is pivotally mounted on the upper end of the rame C of this magnet. A spring 34 extending between the outer end of the stop arm 33 and a pin 35 on the frame C (shown only in the case of the transmitter magnet F) holds the inner end of the arm against the periphery of the stop disk 31.

By this means the sleeve 17 and switch arm a are held against movement, but when the trip magnet C is energized the stop arm 33 is disengaged from the shoulder 32. The

friction connection'between the shaft and sleeve is then effective to rotate the sleeve and switch arm through a singlerevolution whereupon they are again arrested by the engagement of the shoulder 32 with the stop arm 33. The friction drive connection set forth operates effectively to quickly pick up and rotate the switch arm as soon as the trip magnet is energized.

The sleeve 17 also preferably carries an insulated cam N which is arranged to operate a spring switch arm N. The latter is suitably spring-pressed in. a direction to bring it into engagement with contact a when not interfered with by the cam N. The latter is reduced in diameter through the greater portion of its periphery, being provided with a lug 91. Thus the switch N is closed against contact a through the greater portion of the revolution of the receiver switch but is momentarily opened just before the switch completes its revolution.

The receiver switch mechanisn'l above doseribed may be combined with a transmitter switch mechanism into a single station instrument, as fully set forth in the aforesaid parent case.

Shaft 50 forms the driving element of the transmitter switch mechanism which comprises a rotating switch arm 6, and an annular contact disk E. The arrangement of the dis a l is similar to that of the receiver disk A, except that the transmitter disk is not adjustably mounted. Like the receiver switch arm a, the transmitter switch arm 6 is mounted on a sleeve 17 and is connected to'its driving shaft 50 through av similar yielding friction connection, and the sleeve is provided with a like controlling disk 31 and stop arm 33, the stop arm of the transmitter switch mechanism being controlled by a trip magnet F.

The sleeve 17 of the transmitter switch mechanism is also provided with a cam g,

vThus the switch G is in closed position through the greater portion of the revolution of the transmitter switch, but is' momentarily opened just before this switch completes a revolution. i

Each transmitter and receiver disk is provided with live contacts. A set of selecting switches it serves to variahlyronnect contacts 1, 2,3, 1 and 5 of the transmitterdisk to a source of current to thereby determine the combinations of'impulses' imparted to the line as the transmit-terswitch arm 6 passes over these contacts} Preferably, the signals are represented by permutations of five positive and negative impulses and the switches are, therefore, in the form of pole V changers, thenormally engaged contacts thereof being connected by conductors 52 to the positive side of a divided battery H, and the normally disengaged, or front, contacts thereof being connected by conductors 53 to the negative poleof the battery. The selecting switches h are directly connected to the contacts 1, 2, 3, 4t and 5 of the transmitter -disk by a set of conductors 54, and the transmitter switch arm 6 is connected directly to the linecircuit. The transmitter and receiver disks E andA are provided with but five contacts, and the transmitter switch 6 is directed directly, or through a transmitter relay, to a line conductor 86 that leads to the line relay R at the distant station. The line is normally open, as shown, and therelay switch tongue 1" is provided with a spring arranged between two step pins 87, so that it is normally held in central position. The positive and negative impulses shift the switch tongue 7'' in opposite direc tions and connect one of two conductors 88 and 89 to the local battery L.

A set of branch conductors 62 connects the contacts 1, 2, 3, 4 and 5 of the receiver disk to a set of live selecting relays or magnets M M M M and M The cam operated normally closed switch N is connected to the local battery L by a conductor 64:, and contact n of this switch is connected by a conductor 65 to the contacts of a series of normally open locking switches m that are oper ated, respectively, by the magnets M M M M and M" and are connected to the con- 'ductors .62 that lead to the coils of these magnets. The arrangement is such that when any of the selecting magnets is operated,'it will remain connected to the local battery until the unlocking switch N is opened.

The trip magnet G is provided with two coils, one of which is connected to the con ductor 89 and the other to a branch 90 of the conductor 88. The opposite ends of the coils are grounded or connected by a return wire to the battery L. By this arrangement the-first selecting impulse imparted to the line when the transmitter switch 6' passes over its contact 1, and it may be either positive or negative, serves to energize the trip magnet C. l/Vith this arrangement, it is not necessar to em 10 an additional starting impulse as in the normally closed line circuit of the parent case.

The transmitter selecting switchesh are variably operatedbya set of finger keys, one of which is shown at 68, and which are are ranged like the keys in an ordinary typewriter. Thejkeys are provided with lugs 69, these lugs being so arranged that the depression of each key will operate a particular combination of the selecting switches which correspond to the character represented by the key; Each finger key of the transmitter is also arranged to operate a erated.

switch it which is connectedto the coil of the trip magnet F and also to the coil of the magnet P. Preferably, the cut out switch G is arranged in the circuit of the trip magnet F. As shown in the diagram the switch it is connected by a conductor to the coil of the magnet- P, and the latter isconnected by conductor 71 to the switch Gr, the contact of which is connected to the coil of the magnet F by a conductor 72. Switch It has only one normally disengaged contact which is connected by a conductor 7 3 to the local battery H One terminal of the magnet F is grounded or connected by a reimpulses, corresponding to the depressedlcey, is transmitted to the line. The key also shifts the switch it so that current flows from local battery L by conductor 73, switch H, conductor 70, through magnet P, thence by conductor 71, switch G and conductor 72 through the trip magnet F. Magnet F is thus energized to permit the operation of the transmitter switch 6, and magnet P is also energized. to operate the lock device 75. This lock device holds down the shifted key and prevents premature operation of the other keys. Just before the transmitter switch completes its revolution the cam 9 opens the switch G and the magnets P and F are deenergized. The transmitter switch is arrested at the end of a revolution and after it has passed over a number of contacts sufiicient to transmit the combination of im pulses corresponding to a single character. It should be noted, however, that since the switch G is opened to release the locking device before the rotary transmitter switch member reaches its normal position, messages may be rapidly transmitted without appreciable pausesbetween the signals.

The line circuit is normally closed and the tongue 1 of the line relay R at the distantwhether positive or negative, starts the re ceiving distributer. The circuit in one case will extend from battery L through tongue r, conductor 89 and one winding of magnet C, and in the other case through conductors 89 and 90 and the second winding of magnet G. In either case trip magnet C will be op- The stop arm 33 is then released and the receiver switch at once commences to rotate over the contacts of the receiver negative impulses.

nal.

disk. The receiver switch operates in proper phase relation with the transmitter switch at the distant station so that the magnets M M M M and M are variably operated in accordance with the permutations of impulses; that is to say, if the selected impulse is negative the switch tongue r will be moved, say, to its left hand contact as the receiver switch a rests upon contact 1 and magnet M will be operated. This same impulse closes the path through conductors 88 and QU and trips magnet C as before noted. If the first selecting impulse is posit ve, the circuit 01' the magnet M will not be closed when the switch arm a rests upon contact 1 since at this time the relay switch tongue 7'' will be against its right hand contact, but bet'ore noted magnet C will be operated by reason of the path closed through conductor 89. In a similar manner the other magnets M M, M and M are variably operated in accordance with the difierent permutations of live positive and W henever one of the magnets is operated, its switch in closes a circuit from battery L through conductor (34, normally closed switch N, conductor 65, switch m, and conductor (32, through the coil of the magnet which thus remains energized, until the un- Ilgtflfllig or releasing switch N is opened. .lhis occurs alter the receiver switch passes over contact 5 and ust before it leaches its nori'nal position. Thus when any signal is completed, the transmitter and receiver switcl mechanisms and the selecting magnets M", M, M, M and M, are restored to normal condition ready tor the next sig- The variable operation of these selecting niagi'iets can be employed, will be readily ninlerstood, to operate a suitable printing instrument.

The iriction clutch device for operating the receiver switch is such that the latter picks up quickly and commences to operate as soon asthe nocurrent starting impulse which precedes the selecting impulses of each signal is received, to thereby operate the trip magnet C. It should be noted that the members ot this triction clutch or coupling are constantly engaged and slip pasteach other when the stop arm 33 engages the shoulder of the disk 31. The parts of the frictional connection, however, pick up and operate the receiver switch as soon as the trip magnet is energized.

The shaft 180i the receiver switch is driven somewhat faster than the shaft 50 of the transmitter switch at the distant station. But as the receiver switch is arrested at the completion of each signal it is operated in proper synchronism with the receiver switch. Preferably, as shown, the contacts oi the receiver disk are spaced lUU , contacts 5 and 1 upon the transmitter disk,

so that the receiver switch arm can run faster and be arrested at the end of each signal vwhen the transmitter is rapidly operated Ill) without appreciable pauses between the signals. Obviously, the distance in the relative angular spacing of the receiver and transmitter contacts should accord with and thus compensate for the relative difference in speeds at which the respective contact arms are usually operated.

By accelerating the operation of the receiver switch arn'i relatively to that oi the transmitter at the distant station, or having its'period' oi? operation relatively shorter, the receiver switch arm will be invarlably arrested in normal position at the end of each signal and again started in proper phase with the initial impulse received from the distant station at the beginning of each signal. It should also be noted that not only is the angular spacing of the contacts of the receiver disk relatively greater than that of the transmitter disk but the receiver contacts are also conside ably smaller, and that by adjusting the receiver disk in the manner more particularly pointed out in the parent case, the relation between its contacts and the normally arrested position of the receiver switch arm can be so adjusted that the latter can be started and caused to register with the contacts during the midportions only of the selecting impulses or intervals of the received signals. Since the operation of the rotary transmitter member is locally controlled independently of the line conditions and by its movement during each signal period establishes all the changes in the line conditions, including the starting intervals, the receiver contacts need only be adjusted relatively to the normal rest position of the rotary receiver switch member to take care ot variations in the time operation of its own starting means. Furthermore, no great frequency of speed adjustment is required to maintain the receiver member in proper operative relation with the transmitter member at the distance station. Thus the speed of the shaft 18 which operates the receiver can vary as much as 10 or 15 per cent without atiecting the proper operation. For example, in practice the speed of the transmitter shaft is 360 revolutions per minute, and that of: the receiver shaft is 390 revolutions, but the relative speed of the two can vary as much as 10 or 15 per cent without interfering with the proper transmission of messages.

This is a particular advantage in lines having receiver mechanism at a number of different stations all acting in response to a transmitter at a single station, since itis with the SPQGCl OTlI the tansmitter.

not necessary to accurately adjust or attune the receiver at each station in accordance 7 here each station is provided with a combined transi'nitter and receiver, as explained in my parentcase, satisfactory operation may be obtained. In the particular form illustrated in said parent case the receiver shaft rotates considerably faster than the transll'llti'Ql shatlt and in the ratio of 39 revolutions for each 36 revolutions of the transmitter shaft. If two such, instruments are employed at connecting stations and the station motors are operated at substantially the same speed, the rotary receiver member at each station will be driven faster than the transmitter member at the distant station and by means of the start and stop clutch individual thereto, can be brought into proper phase relation with the transmitter at the distant station between successive signals. lVhile the rotary transmitter and re ceivcr members of a combined station instrument are driven from a common motor, separator individual start and stop clutches are provided for arresting the same in normal position. With this arrangement the transmitter clutch can be and is controlled locally and independently of the line impulses, while the receiver clutch is controlled by the first non-current impulse imparted to the line by the movementof the distant transmitter from normal position.

it is obvious that numerous changes may be made in the details set forth without dcparture from the essentials of the invention as defined in the claims.

Iclaim as my invention:

"l. A telegraph system wherein the characters are represented by permutations of a definite number of two diiferent impulses, including a line conductor, means for sending code impulses over said conductor, re-

ceiving distributing mechanism comprising contacts and a member adapted to be continuously advanced during each operation to successively complete circuit through said contacts, electro-magnets in circuit with said contacts, said mechanism having a rest position in which a circuit through one of said electro-magnets is completed through said mechanism, a receiving relay responsive in two different ways to the code impulses, and means responsive to both operations of said relay to start said mechanism and to one only of said operations to complete an energizing circuit through the rest position of said mechanism and the connected electromagnet.

2. A telegraph system wherein the characters are represented by permutations of a definite number of positive and negative impulses, including a lineconductor, means for sending code impulses oi? positive and negative current over said line conductor, re-

ceiving distributing mechanism comprising contacts and a member adaptedtobe con tinuously advanced during each operation to successively'complete circuit through said contacts, friction means tending to drive said distributing mechanism, stop means operable only to hold said distributing mechanismin a normal rest position, a trip magnet for tripping said stop means to free said distributing mechanism, receiving magnets in circuit with said contacts, one of said contacts beingiclosed inthe rest position of said distributing mechanism, a polarized receiving relay in said line conductor, means responsive to one operation of said relay both to complete the circuit through the magnet in circuit with the said rest contact of said distributing mechanism and to complete a circuit through said trip magnet, and means responsive to the other operation of said relay to close a circuit through said trip magnet.

3. A telegraph system including a linecon;

ductor. means for sending code permutations of a definite number of positive and nega-- tive impulses over said line conductor, re ceiving distributing member operative solely under local control when free, a polarized pulse of each code permutation to uniformly operate said freeing means.

4. A telegraph system including a line conductor, means for sending code impulses of different character over said conductor, a receiving distributor member adapted to be advanced solely under local control when free, means for freeing the same,'a relay operative in different ways In response to the. impulses of different character sent over said conductor, and means responsive to all operations of said relay by the initial im- .pulse of each code combination for uni-' formly operating said freeing means.

5. A telegraph system including a line conductor, transmitting and receiving distributing mechanisms associated with said conductor, each said mechanism having a series 7 of contacts and means for successively closing the same, both said mechanisms having the same number of said contacts, the midcontact closing positions of the receiving contacts being equally spaced angularly and relatively farther apart than the like positions of the transmitting contacts, the latter being equally spaced angularly, except that spacebetween the last and first contact, said space being greater than the others, and means for utilizing all the contacts of both said mechanisms in sending and receiving the selecting impulses necessary to the characters transmitted.

6. In a start-stop telegraph system, the combination of a rotary, motor-driven, sending distributing member and cooperating contact means adapted, upon the movement of said distributing member from a normal position, toimpart a definite number of selooting impulses for each signal, and a receiver comprising a set of selectors, a rotary, motel-driven, distributing member, electro magnetic means cooperating with said distributing member to variably control said selectors in response to the selecting code impulses of each signal, and a stop device operative only at the end of each signal for arresting said receiving distributing memher and arranged to be uniformly released by said electro-magnetic means in response to the first selecting impulse ofeach signal.

7. In a start-stop.telegraph system, the combination with a normally open line and means for imparting a definite number of successive positive and negative selecting impulses for each signal and for restoring the line tonormal condition between signals, of aset of receiver selectors, a cooperating rotary, motor-driven distributing member, a stop operative only at the end of each signal to arrest said member, a polarized relay for variably controlling said selectors in response to the positive and negative impulses and an electro-rmignet controlled by said relay and uniformly operated by first selecting impulse of each signal. for releasing said step.

8. In a start-stop telegraph system, the combination with a line circuit, of a rotary, motor-driven, sending distributor and cooperating contact means normally holding the line circuit open and adapted, upon the movement of the sending distributor from a normal position, to impart a definite number of successive, positive and negative, selecting impulses to the line circuit for each signal and to restore the line to normal open condition between signals, and a, receiver comprising a set of selectors, a rotary, motor driven, distributing member, electro-magnetic means cooperating with said member to variably control said selectors in response to the positiveand negative, selecting impulses of each signal, and a stop device 0pefiative only at the end of each signal to arrest said receiving distributing member and arranged to be uniformly released by the first selecting impulses of either polarity of the signals.

9. In a telegraph system, the combination With a line circuit, of rotary, start-stop, sending and receiving distributor members, means for continuously advancing said rotary members during each signal period, con tact means controlled and timed in operation by the rotary movement of said sending member to in'ipart a definite number of successive positive and negative impulses to the line for each signal, a set of selectors operatively associated in order with the line by the rotary movement of said receiving member, a stop device operative only at the end of each signal for arresting the said receiving member and electro -magnet1c means responsive to the initial impulse of either polarity of each signal for invariably releasing said stop device and for variably controlling the setting of said selectors.

10. In a telegraph system, the comb1nation with a line circuit, of rotary, start-stop, sending and receiving distributor members, means for continuously advancing said rotary members during each signal period, contact means controlled and timed in oper ation by the rotary movement of said sending member to impart a definitenumber of successive positive and negative impulses to the line for each signal, a set of selectors operatively associated in order with the line by the rotary movement of said recelvlng member, a stop device operative only at the end of each signal for arresting the said receiving member and electromagnetic means responsive to the initial impulse of either polarity of each signal for invariably releasin said stop device and for variably contro ling the scttinv of said selectors, the operating positions oi member being angularly spaced farther apart than those of the transmitting member to permit the former to be driven at relatively greater angular speed,

11. In a start-stop telegraph system, the combination with a line circuit, of rotary, motor-driven, sending and receiving distributors adapted to be continuously advanced'during each signal period, contact means normally holding the line open and controlled and timed in operation by the rotary movement of the sending distributor from a normal position, to thereby impart a definite number of successive positive and said rotary receiving motor-driven, sending and receiving distributors adapted to be continuously advanced during each signal period, contact means normally holding the line open and con-' trolled and timed in operation by the rotary movement of the sending distributor from a normal position, to thereby impart a definite number of successive positive and negative impulses to the line for each signal and to restore the line to normal open condition for a definite interval between signals, a set of selectors operatively associated in order with the line by said rotary receiver member, a stop device operative only at the end of each signal to arrest said receiver member and electro-magnetic means for uniformly releasing said sto device in response to the initial impulse 0 either polarity of each signal and fol-variably controlling the setting of said selectors-in different combinations, the operating positions of said rotary receiver member being .angularly spaced farther apart than those of the transmitting member to permit the former to be driven at relatively greater angular speeds and be invariably arrested during the open line conditions at the end of each signal.

13. In a start-stop telegraph system, the combination with a line, of a rotary transmitter member adapted by its rotary movement to impart a definitenumber of successive positive and negative impulses to the line for each signal, a set of receiving selectors, a start-stop rotary member operated, when started, solely under local control to associate said selectors in order with the line, and an electromagnetic means for invariably starting said receiver member in response to the initial impulses of either polarity of the signals and for variably controlling the setting of said selectors, each in either one of two positions, in accordance with the'polarity of the corresponding signal impulses.

HOWARD L. KRUM. 

